... .PHR Series Portable Rockwell Hardness Tester has produced two specifications. Model PHR-1 and PHR-2, the opening sizes are 1 ... Protable rockwell hardness gaugeHardness scaleRockweel—A, B , C , D , E , F , G , H , KSuperficial rockwell—15N , 30N , 45N , 15T , 30T , 45TTest forceRockwell ...